Random numbers are necessary for data encryption. Random numbers include so-called pseudo-random numbers which are generated by programs and the pseudo-random numbers are commonly used.
However, the pseudo-random numbers are not suitable for encryption because rules for generating such pseudo-random numbers can be easily estimated. In terms of security, genuine random numbers with no generation rule are more preferable.
Random phenomena occurred in nature may be used as physical random numbers. And it is necessary to have a physical random number generator with a simple structure which can provide random numbers to personal computers or portable terminals for various applications including encryption programs for confidential documents, games, electronic authentication, and numeral simulation (Monte Calro method) and the like.
The present invention has been accomplished in view of the above problem, and it is an object of the invention to provide a random number generator with a simple structure to generate physical random numbers necessary for encryption.